I don't disagree with you. I think that product managers would need more information, other than, the workflows would run on another server. When considering such a drastic change to the fundamental structure of the software, for one customer, it might make sense, for another, it would mean a bigger investment into more hardware, maintenance and support of that hardware etc.

If I was a product manager (and I'm not ), I would be interested in learning how many workflows you are looking at running every month, and exactly what those workflows do, since the current SharePoint workflow engine isn't providing the type of performance that you need.

Then as a product manager, I would be in a better position to guide the direction of the software.